1. Field of the Invention
The present invention relates to a gas sensor having a stacked-type gas detecting element in which a plurality of ceramic layers are stacked.
2. Description of the Related Art
Conventionally, a plate-like gas detecting element is known which extends in a longitudinal direction. A plurality of ceramic layers are stacked to form a plate-like detecting element, and a detecting portion is formed at a leading end side thereof Such gas detecting elements are disclosed, for example, in JP-A-61-134655, JP-A-2001-242129, JP-A-2001-311714 and JP-A-2002-107335. Through holes penetrating the ceramic layers are provided in the gas detecting element. In each of these through holes, a conductor is provided for electrically connecting a lead portion extending from a sensing electrode disposed in the interior of the gas detecting element and an electrode pad disposed on an outer surface of the gas detecting element.